diff --git a/memory.c b/memory.c
deleted file mode 100644
index ac98d55..0000000
--- a/memory.c
+++ /dev/null
@@ -1,492 +0,0 @@
-/*
- *  linux/mm/memory.c
- *
- *  (C) 1991  Linus Torvalds
- */
-
-/*
- * demand-loading started 01.12.91 - seems it is high on the list of
- * things wanted, and it should be easy to implement. - Linus
- */
-
-/*
- * Ok, demand-loading was easy, shared pages a little bit tricker. Shared
- * pages started 02.12.91, seems to work. - Linus.
- *
- * Tested sharing by executing about 30 /bin/sh: under the old kernel it
- * would have taken more than the 6M I have free, but it worked well as
- * far as I could see.
- *
- * Also corrected some "invalidate()"s - I wasn't doing enough of them.
- */
-
-#include <signal.h>
-
-#include <asm/system.h>
-
-#include <linux/sched.h>
-#include <linux/head.h>
-#include <linux/kernel.h>
-
-volatile void do_exit(long code);
-
-static inline volatile void oom(void)
-{
-	printk("out of memory\n\r");
-	do_exit(SIGSEGV);
-}
-
-#define invalidate() \
-__asm__("movl %%eax,%%cr3"::"a" (0))
-
-/* these are not to be changed without changing head.s etc */
-#define LOW_MEM 0x100000
-#define PAGING_MEMORY (15*1024*1024)
-#define PAGING_PAGES (PAGING_MEMORY>>12)
-#define MAP_NR(addr) (((addr)-LOW_MEM)>>12)
-#define USED 100
-
-#define CODE_SPACE(addr) ((((addr)+4095)&~4095) < \
-current->start_code + current->end_code)
-
-static long HIGH_MEMORY = 0;
-
-#define copy_page(from,to) \
-__asm__("cld ; rep ; movsl"::"S" (from),"D" (to),"c" (1024))
-
-static unsigned char mem_map [ PAGING_PAGES ] = {0,};
-
-/*
- * Get physical address of first (actually last :-) free page, and mark it
- * used. If no free pages left, return 0.
- */
-unsigned long get_free_page(void)
-{
-register unsigned long __res asm("ax");
-
-__asm__("std ; repne ; scasb\n\t"
-	"jne 1f\n\t"
-	"movb $1,1(%%edi)\n\t"
-	"sall $12,%%ecx\n\t"
-	"addl %2,%%ecx\n\t"
-	"movl %%ecx,%%edx\n\t"
-	"movl $1024,%%ecx\n\t"
-	"leal 4092(%%edx),%%edi\n\t"
-	"rep ; stosl\n\t"
-	"movl %%edx,%%eax\n\t"
-	"1:"
-	"cld\n\t"       /* by wyj */
-	:"=a" (__res)
-	:"0" (0),"i" (LOW_MEM),"c" (PAGING_PAGES),
-	"D" (mem_map+PAGING_PAGES-1)
-	);
-return __res;
-}
-
-/*
- * Free a page of memory at physical address 'addr'. Used by
- * 'free_page_tables()'
- */
-void free_page(unsigned long addr)
-{
-	if (addr < LOW_MEM) return;
-	if (addr >= HIGH_MEMORY)
-		panic("trying to free nonexistent page");
-	addr -= LOW_MEM;
-	addr >>= 12;
-	if (mem_map[addr]--) return;
-	mem_map[addr]=0;
-	panic("trying to free free page");
-}
-
-/*
- * This function frees a continuos block of page tables, as needed
- * by 'exit()'. As does copy_page_tables(), this handles only 4Mb blocks.
- */
-int free_page_tables(unsigned long from,unsigned long size)
-{
-	unsigned long *pg_table;
-	unsigned long * dir, nr;
-
-	if (from & 0x3fffff)
-		panic("free_page_tables called with wrong alignment");
-	if (!from)
-		panic("Trying to free up swapper memory space");
-	size = (size + 0x3fffff) >> 22;
-	dir = (unsigned long *) ((from>>20) & 0xffc); /* _pg_dir = 0 */
-	for ( ; size-->0 ; dir++) {
-		if (!(1 & *dir))
-			continue;
-		pg_table = (unsigned long *) (0xfffff000 & *dir);
-		for (nr=0 ; nr<1024 ; nr++) {
-			if (1 & *pg_table)
-				free_page(0xfffff000 & *pg_table);
-			*pg_table = 0;
-			pg_table++;
-		}
-		free_page(0xfffff000 & *dir);
-		*dir = 0;
-	}
-	invalidate();
-	return 0;
-}
-
-/*
- *  Well, here is one of the most complicated functions in mm. It
- * copies a range of linerar addresses by copying only the pages.
- * Let's hope this is bug-free, 'cause this one I don't want to debug :-)
- *
- * Note! We don't copy just any chunks of memory - addresses have to
- * be divisible by 4Mb (one page-directory entry), as this makes the
- * function easier. It's used only by fork anyway.
- *
- * NOTE 2!! When from==0 we are copying kernel space for the first
- * fork(). Then we DONT want to copy a full page-directory entry, as
- * that would lead to some serious memory waste - we just copy the
- * first 160 pages - 640kB. Even that is more than we need, but it
- * doesn't take any more memory - we don't copy-on-write in the low
- * 1 Mb-range, so the pages can be shared with the kernel. Thus the
- * special case for nr=xxxx.
- */
-int copy_page_tables(unsigned long from,unsigned long to,long size)
-{
-	unsigned long * from_page_table;
-	unsigned long * to_page_table;
-	unsigned long this_page;
-	unsigned long * from_dir, * to_dir;
-	unsigned long nr;
-
-	if ((from&0x3fffff) || (to&0x3fffff))
-		panic("copy_page_tables called with wrong alignment");
-	from_dir = (unsigned long *) ((from>>20) & 0xffc); /* _pg_dir = 0 */
-	to_dir = (unsigned long *) ((to>>20) & 0xffc);
-	size = ((unsigned) (size+0x3fffff)) >> 22;
-	for( ; size-->0 ; from_dir++,to_dir++) {
-		if (1 & *to_dir)
-			panic("copy_page_tables: already exist");
-		if (!(1 & *from_dir))
-			continue;
-		from_page_table = (unsigned long *) (0xfffff000 & *from_dir);
-		if (!(to_page_table = (unsigned long *) get_free_page()))
-			return -1;	/* Out of memory, see freeing */
-		*to_dir = ((unsigned long) to_page_table) | 7;
-		nr = (from==0)?0xA0:1024;
-		for ( ; nr-- > 0 ; from_page_table++,to_page_table++) {
-			this_page = *from_page_table;
-			if (!(1 & this_page))
-				continue;
-			this_page &= ~2;
-			*to_page_table = this_page;
-			if (this_page > LOW_MEM) {
-				*from_page_table = this_page;
-				this_page -= LOW_MEM;
-				this_page >>= 12;
-				mem_map[this_page]++;
-			}
-		}
-	}
-	invalidate();
-	return 0;
-}
-
-/*
- * This function puts a page in memory at the wanted address.
- * It returns the physical address of the page gotten, 0 if
- * out of memory (either when trying to access page-table or
- * page.)
- */
-unsigned long put_page(unsigned long page,unsigned long address)
-{
-	unsigned long tmp, *page_table;
-
-/* NOTE !!! This uses the fact that _pg_dir=0 */
-
-	if (page < LOW_MEM || page >= HIGH_MEMORY)
-		printk("Trying to put page %p at %p\n",page,address);
-	if (mem_map[(page-LOW_MEM)>>12] != 1)
-		printk("mem_map disagrees with %p at %p\n",page,address);
-	page_table = (unsigned long *) ((address>>20) & 0xffc);
-	if ((*page_table)&1)
-		page_table = (unsigned long *) (0xfffff000 & *page_table);
-	else {
-		if (!(tmp=get_free_page()))
-			return 0;
-		*page_table = tmp|7;
-		page_table = (unsigned long *) tmp;
-	}
-	page_table[(address>>12) & 0x3ff] = page | 7;
-/* no need for invalidate */
-	return page;
-}
-
-void un_wp_page(unsigned long * table_entry)
-{
-	unsigned long old_page,new_page;
-
-	old_page = 0xfffff000 & *table_entry;
-	if (old_page >= LOW_MEM && mem_map[MAP_NR(old_page)]==1) {
-		*table_entry |= 2;
-		invalidate();
-		return;
-	}
-	if (!(new_page=get_free_page()))
-		oom();
-	if (old_page >= LOW_MEM)
-		mem_map[MAP_NR(old_page)]--;
-	*table_entry = new_page | 7;
-	invalidate();
-	copy_page(old_page,new_page);
-}	
-
-/*
- * This routine handles present pages, when users try to write
- * to a shared page. It is done by copying the page to a new address
- * and decrementing the shared-page counter for the old page.
- *
- * If it's in code space we exit with a segment error.
- */
-void do_wp_page(unsigned long error_code,unsigned long address)
-{
-#if 0
-/* we cannot do this yet: the estdio library writes to code space */
-/* stupid, stupid. I really want the libc.a from GNU */
-	if (CODE_SPACE(address))
-		do_exit(SIGSEGV);
-#endif
-	un_wp_page((unsigned long *)
-		(((address>>10) & 0xffc) + (0xfffff000 &
-		*((unsigned long *) ((address>>20) &0xffc)))));
-
-}
-
-void write_verify(unsigned long address)
-{
-	unsigned long page;
-
-	if (!( (page = *((unsigned long *) ((address>>20) & 0xffc)) )&1))
-		return;
-	page &= 0xfffff000;
-	page += ((address>>10) & 0xffc);
-	if ((3 & *(unsigned long *) page) == 1)  /* non-writeable, present */
-		un_wp_page((unsigned long *) page);
-	return;
-}
-
-void get_empty_page(unsigned long address)
-{
-	unsigned long tmp;
-
-	if (!(tmp=get_free_page()) || !put_page(tmp,address)) {
-		free_page(tmp);		/* 0 is ok - ignored */
-		oom();
-	}
-}
-
-/*
- * try_to_share() checks the page at address "address" in the task "p",
- * to see if it exists, and if it is clean. If so, share it with the current
- * task.
- *
- * NOTE! This assumes we have checked that p != current, and that they
- * share the same executable.
- */
-static int try_to_share(unsigned long address, struct task_struct * p)
-{
-	unsigned long from;
-	unsigned long to;
-	unsigned long from_page;
-	unsigned long to_page;
-	unsigned long phys_addr;
-
-	from_page = to_page = ((address>>20) & 0xffc);
-	from_page += ((p->start_code>>20) & 0xffc);
-	to_page += ((current->start_code>>20) & 0xffc);
-/* is there a page-directory at from? */
-	from = *(unsigned long *) from_page;
-	if (!(from & 1))
-		return 0;
-	from &= 0xfffff000;
-	from_page = from + ((address>>10) & 0xffc);
-	phys_addr = *(unsigned long *) from_page;
-/* is the page clean and present? */
-	if ((phys_addr & 0x41) != 0x01)
-		return 0;
-	phys_addr &= 0xfffff000;
-	if (phys_addr >= HIGH_MEMORY || phys_addr < LOW_MEM)
-		return 0;
-	to = *(unsigned long *) to_page;
-	if (!(to & 1))
-		if (to = get_free_page())
-			*(unsigned long *) to_page = to | 7;
-		else
-			oom();
-	to &= 0xfffff000;
-	to_page = to + ((address>>10) & 0xffc);
-	if (1 & *(unsigned long *) to_page)
-		panic("try_to_share: to_page already exists");
-/* share them: write-protect */
-	*(unsigned long *) from_page &= ~2;
-	*(unsigned long *) to_page = *(unsigned long *) from_page;
-	invalidate();
-	phys_addr -= LOW_MEM;
-	phys_addr >>= 12;
-	mem_map[phys_addr]++;
-	return 1;
-}
-
-/*
- * share_page() tries to find a process that could share a page with
- * the current one. Address is the address of the wanted page relative
- * to the current data space.
- *
- * We first check if it is at all feasible by checking executable->i_count.
- * It should be >1 if there are other tasks sharing this inode.
- */
-static int share_page(unsigned long address)
-{
-	struct task_struct ** p;
-
-	if (!current->executable)
-		return 0;
-	if (current->executable->i_count < 2)
-		return 0;
-	for (p = &LAST_TASK ; p > &FIRST_TASK ; --p) {
-		if (!*p)
-			continue;
-		if (current == *p)
-			continue;
-		if ((*p)->executable != current->executable)
-			continue;
-		if (try_to_share(address,*p))
-			return 1;
-	}
-	return 0;
-}
-
-/*
-do_no_page()是页异常中断过程中调用的缺页处理函数。它首先判断指定的线性地址在一个进程空
-间中相对于进程基址的偏移长度值。如果它大于代码加数据长度，或者进程刚开始创建，则立刻申请一
-页物理内存，并映射到进程线性地址中，然后返回；接着尝试进行页面共享操作，若成功，则立刻返回；
-否则申请一页内存并从设备中读入一页信息；若加入该页信息时，指定线性地址+1 页长度超过了进程代
-码加数据的长度，则将超过的部分清零。然后将该页映射到指定的线性地址处。
-*/
-
-void do_no_page(unsigned long error_code,unsigned long address)
-{
-	int nr[4];
-	unsigned long tmp;
-	unsigned long page;
-	int block,i;
-
-	address &= 0xfffff000;	// address 处缺页页面地址。
-	tmp = address - current->start_code;	// 缺页页面对应逻辑地址。
-	if (!current->executable || tmp >= current->end_data) {
-		get_empty_page(address);
-		return;
-	}
-	if (share_page(tmp))		// 尝试逻辑地址 tmp 处页面的共享。
-		return;
-	if (!(page = get_free_page()))	// 申请一页物理内存
-		oom();
-/* remember that 1 block is used for header */
-	block = 1 + tmp/BLOCK_SIZE;
-	for (i=0 ; i<4 ; block++,i++)
-		nr[i] = bmap(current->executable,block);
-	bread_page(page,current->executable->i_dev,nr);
-	i = tmp + 4096 - current->end_data;
-	tmp = page + 4096;
-	while (i-- > 0) {
-		tmp--;
-		*(char *)tmp = 0;
-	}
-	if (put_page(page,address))
-		return;
-	free_page(page);
-	oom();
-}
-
-/* for exec.c/do_execve2 */
-/* coded by dj */
-void my_do_no_page(unsigned long address)
-{
-	int nr[4];
-	unsigned long tmp;
-	unsigned long page;
-	int block,i;
-
-	address &= 0xfffff000;					// address 处缺页页面地址。
-	tmp = address - current->start_code;	// 缺页页面对应逻辑地址。
-
-	/* 
-	若当前进程的executable 空，或者指定地址超出代码+数据长度，则申请一页物理
-	内存，并映射到指定的线性地址处。executable 是进程的i 节点结构。该值为0，表明
-	进程刚开始设置，需要内存；而指定的线性地址超出代码加数据长度，表明进程在申请新
-	的内存空间，也需要给予。因此就直接调用get_empty_page()函数，申请一页物理内存
-	并映射到指定线性地址处即可。
-	*/
-
-	if (!current->executable || tmp >= current->end_data) {
-		get_empty_page(address);
-		return;
-	}
-	if (share_page(tmp))		// 尝试逻辑地址 tmp 处页面的共享。
-		return;
-	if (!(page = get_free_page()))	// 申请一页物理内存
-		oom();
-/* remember that 1 block is used for header */
-
-/* 记住，（程序）头要使用 1 个数据块 */
- // 根据这个块号和执行文件的 i 节点，我们就可以从映射位图中找到对应块设备中对应的设备
- // 逻辑块号（保存在 nr[]数组中）。利用 bread_page()即可把这 4 个逻辑块读入到物理页面
- // page 中。
-	block = 1 + tmp/BLOCK_SIZE;
-	for (i=0 ; i<4 ; block++,i++)
-		nr[i] = bmap(current->executable,block);
-	bread_page(page,current->executable->i_dev,nr);
-	i = tmp + 4096 - current->end_data;		// 超出的字节长度值。
-	tmp = page + 4096;						// tmp 指向页面末端。
-	while (i-- > 0) {						// 页面末端 i 字节清零。
-		tmp--;
-		*(char *)tmp = 0;
-	}
-
-	// 最后把引起缺页异常的一页物理页面映射到指定线性地址 address 处。若操作成功就返回，
- 	// 否则就释放内存页，显示内存不够。
-	if (put_page(page,address))
-		return;
-	free_page(page);
-	oom();
-}
-
-void mem_init(long start_mem, long end_mem)
-{
-	int i;
-
-	HIGH_MEMORY = end_mem;
-	for (i=0 ; i<PAGING_PAGES ; i++)
-		mem_map[i] = USED;
-	i = MAP_NR(start_mem);
-	end_mem -= start_mem;
-	end_mem >>= 12;
-	while (end_mem-->0)
-		mem_map[i++]=0;
-}
-
-void calc_mem(void)
-{
-	int i,j,k,free=0;
-	long * pg_tbl;
-
-	for(i=0 ; i<PAGING_PAGES ; i++)
-		if (!mem_map[i]) free++;
-	printk("%d pages free (of %d)\n\r",free,PAGING_PAGES);
-	for(i=2 ; i<1024 ; i++) {
-		if (1&pg_dir[i]) {
-			pg_tbl=(long *) (0xfffff000 & pg_dir[i]);
-			for(j=k=0 ; j<1024 ; j++)
-				if (pg_tbl[j]&1)
-					k++;
-			printk("Pg-dir[%d] uses %d pages\n",i,k);
-		}
-	}
-}